Pre-assembled piston accumulator insert device

ABSTRACT

A damper with inner and outer tubes and a piston disposed within the inner tube to define first and second working chambers. A fluid transport chamber is positioned between the inner and outer tubes. A collector chamber is positioned outside the outer tube. An intake valve assembly, abutting one end of the inner tube, is positioned inside the outer tube. An accumulator insert with an open end abutting the intake valve assembly is positioned inside the outer tube. The accumulator insert includes an accumulator sleeve, a floating piston, and a pressurized chamber. The floating piston is disposed inside the accumulator sleeve and the pressurized chamber is positioned between the floating piston and a closed end of the accumulator sleeve. An accumulation chamber is positioned between the intake valve assembly and the floating piston and the accumulator sleeve includes one or more apertures arranged in fluid communication with the collector chamber.

FIELD

The present disclosure generally relates to dampers. More particularly,the present disclosure relates to a damper with a floating pistonaccumulator and multiple external control valves mounted to a sidecollector.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Vehicles generally include dampers that are used in conjunction withsuspension systems to absorb vibrations that occur while driving thevehicle. In order to absorb the vibrations, dampers are generallyconnected between a body and the suspension system of the vehicle. Apiston is located within the damper. The piston is connected to thevehicle body or the suspension of the vehicle through a piston rod. Thedamper also includes a damper body that is connected to the suspensionsystem. As the damper is compressed or extended, the piston may limitthe flow of damping fluid between first and second working chambers thatare defined within the damper body in order to produce a damping forcethat counteracts the vibrations. By further restricting the flow ofdamping fluid between the first and second working chambers of thedamper, greater damping forces may be generated by the damper.

Dampers typically include one or more valves that control flow of fluidduring extension and compression motions of the piston. Current damperdesigns include a valve block that provides mutual hydraulic connectionsbetween the first and second working chambers, the valves, and anaccumulator. Such designs often make the damper bulky and increase theoverall cost of the damper. Current dampers also have check valves thatfurther increase the size and cost of the damper.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

In accordance with one aspect of the present disclosure, a damper isprovided. The damper includes an inner tube that extends longitudinallybetween first and second inner tube ends. The damper includes a pistonslidably disposed within the inner tube. The piston defines a firstworking chamber and a second working chamber within the inner tube. Thefirst working chamber is longitudinally positioned between the pistonand the first inner tube end and the second working chamber islongitudinally positioned between the piston and the second inner tubeend. The damper also includes an outer tube disposed around the innertube. The outer tube extends longitudinally between first and secondouter tube ends. The first working chamber is arranged in fluidcommunication with a fluid transport chamber that is disposed radiallybetween the inner tube and the outer tube. The damper further includes acollector chamber that is positioned outside of the outer tube.

The damper includes an intake valve assembly that is positioned withinthe outer tube. The intake valve assembly includes one or moreintermediate chambers that are disposed in fluid communication with thecollector chamber. The intake valve assembly also includes one or moreintake valves that control fluid flow through the intake valve assemblybetween the intermediate chamber(s) and the fluid transport chamber.

The damper includes an accumulator insert comprising an accumulatorsleeve, a floating piston, and a pressurized chamber. The accumulatorsleeve is positioned inside the outer tube and extends between a closedend adjacent to the second outer tube end and an open end adjacent tothe intake valve assembly. The floating piston is disposed inside theaccumulator sleeve between the intake valve assembly and the closed endof the accumulator sleeve. The pressurized chamber is positionedlongitudinally between the floating piston and the closed end of theaccumulator sleeve. The pressurized chamber contains a pressurizedfluid, such as a pressurized gas, which operates to bias the floatingpiston towards the intake valve assembly. In accordance with thisarrangement, an accumulation chamber is positioned longitudinallybetween the intake valve assembly and the floating piston. Theaccumulation chamber is arranged in fluid communication with thecollector chamber. For example, the accumulation chamber is arranged influid communication with the collector chamber by an accumulator port inthe outer tube and one or more apertures in the accumulator sleeve thatare arranged in fluid communication with the accumulator port.

During compression strokes of the damper, one or more intake valvescontrol fluid flow through the intake valve assembly to the fluidtransport chamber. During extension strokes of the damper, one or moreintake valves control fluid flow through the intake valve assembly tothe second working chamber. The damper may also include first and secondcontrol valves that are externally mounted to the outer tube. The firstcontrol valve has a first control valve inlet that is arranged in fluidcommunication with the fluid transport chamber via a first port in theouter tube and a first control valve outlet that is arranged in fluidcommunication with the collector chamber. The second control valve has asecond control valve inlet that is arranged in fluid communication withthe intermediate chamber(s) via a second port in the outer tube and asecond control valve outlet that is arranged in fluid communication withthe collector chamber. As a result, the first control valve controls thedampening level during extension strokes and the second control valvecontrols the damping level during compression strokes.

In accordance with another aspect of the present disclosure, a method ofmanufacturing the disclosed dampers is provided. In accordance with thedisclosed designs, the floating piston can be preassembled inside theaccumulator sleeve and the pressurized chamber can be charged withpressurized gas as part of the preassembly process. Once preassembled,the accumulator insert can then be slid into the outer tube of thedamper. The disclosed designs also eliminate the need for mechanicallyattaching the intake valve assembly to the outer tube, such as bywelding. Instead, in the disclosed designs, the intake valve assembly isclamped between the open end of the accumulator sleeve and the secondinner tube end. This results in manufacturing efficiencies over thedesign disclosed by Tenneco Automotive Operating Company, Inc. in U.S.patent application Ser. No. 16/458,782, filed on Jul. 1, 2019. By movingthe floating piston to an accumulator insert sub-assembly, the presentdesign also makes it easier to coat the outer tube with paint/coatingsthat require high temperature curing because typical seals used on thefloating piston cannot withstand high temperatures. Additionally,because the floating piston slides against the inside surface of theaccumulator sleeve instead of the inside surface of the outer tube,attachments can be welded to the outer tube without affecting thesealing surface for the floating piston.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is an illustration of a vehicle incorporating a suspension systemconstructed in accordance with the present disclosure;

FIG. 2 is a front perspective view of an exemplary damper constructed inaccordance with the present disclosure;

FIG. 3 is a side cross-sectional view of the exemplary damper shown inFIG. 2;

FIG. 4 is an enlarged side cross-sectional view of the exemplary dampershown in FIG. 3, where arrows are included illustrating the fluid flowpath through the damper during a compression stroke;

FIG. 5 is another enlarged side cross-sectional view of the exemplarydamper shown in FIG. 3, where arrows are included illustrating the fluidflow path through the damper during an extension stroke;

FIG. 6 is a front exploded perspective view of an exemplary intake valveassembly and accumulator insert of the exemplary damper shown in FIG. 3;

FIG. 7 is a rear exploded perspective view of the exemplary intake valveassembly and accumulator insert of the exemplary damper shown in FIG. 3;

FIG. 8 is a side cross-sectional view of another exemplary damperconstructed in accordance with the present disclosure;

FIG. 9 is an enlarged side cross-sectional view of the exemplary dampershown in FIG. 8, where arrows are included illustrating the fluid flowpath through the damper during a compression stroke;

FIG. 10 is another enlarged side cross-sectional view of the exemplarydamper shown in FIG. 8, where arrows are included illustrating the fluidflow path through the damper during an extension stroke;

FIG. 11 is a front exploded perspective view of another exemplary intakevalve assembly and accumulator insert of the exemplary damper shown inFIG. 8; and

FIG. 12 is a rear exploded perspective view of the exemplary intakevalve assembly and accumulator insert of the exemplary damper shown inFIG. 8.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to same or like parts.

Example embodiments will now be described more fully with reference tothe accompanying drawings. Example embodiments are provided so that thisdisclosure will be thorough, and will fully convey the scope to thosewho are skilled in the art. Numerous specific details are set forth suchas examples of specific components, devices, and methods, to provide athorough understanding of embodiments of the present disclosure. It willbe apparent to those skilled in the art that specific details need notbe employed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

FIG. 1 illustrates an exemplary vehicle 100 incorporating a suspensionsystem 102 in accordance with the present disclosure. The vehicle 100may be driven by an internal combustion engine, an electric motor, ahybrid/electric powertrain, or equivalents thereof. The vehicle 100includes a body 104. The suspension system 102 of the vehicle 100includes a rear suspension 106 and a front suspension 108. The rearsuspension 106 includes a transversely extending rear axle assembly (notshown) adapted to operatively support a pair of rear wheels 110. Therear axle assembly is operatively connected to the body 104 by means ofa pair of dampers 112 and a pair of helical coil springs 114. Similarly,the front suspension 108 includes a transversely extending front axleassembly (not shown) that supports a pair of front wheels 116. The frontaxle assembly is connected to the body 104 by means of another pair ofdampers 112 and a pair of helical coil springs 118. In an alternativeembodiment, the vehicle 100 may include an independent suspension unit(not shown) for each of the four corners instead of the front and rearaxle assemblies.

The dampers 112 of the suspension system 102 serve to dampen therelative movement of the unsprung portion (i.e., the front and rearsuspensions 108, 106 and the front and rear wheels 116, 110) and thesprung portion (i.e., the body 104) of the vehicle 100. While thevehicle 100 has been depicted as a passenger car, the dampers 112 may beused with other types of vehicles. Examples of such vehicles includebuses, trucks, off-road vehicles, three-wheelers, ATVs, motor bikes, andso forth. Furthermore, the term “damper” as used herein will refer todampers in general and will include shock absorbers, McPherson struts,and semi-active and active suspensions.

In order to automatically adjust each of the dampers 112, an electroniccontroller 120 is electrically connected to the dampers 112. Theelectronic controller 120 is used for controlling the operation of eachof the dampers 112 in order to provide appropriate dampingcharacteristics resulting from movements of the body 104 of the vehicle100. The electronic controller 120 may independently control each of thedampers 112 in order to independently control a damping level of each ofthe dampers 112. The electronic controller 120 may be electricallyconnected to the dampers 112 via wired connections, wirelessconnections, or a combination thereof.

The electronic controller 120 may independently adjust the dampinglevel, damping rate, or damping characteristics of each of the dampers112 to optimize the ride performance of the vehicle 100. The term“damping level”, as used herein, refers to a damping force produced byeach of the dampers 112 to counteract movements or vibrations of thebody 104. A higher damping level may correspond to a higher dampingforce. Similarly, a lower damping level may correspond to a lowerdamping force. Adjustment of the damping levels is beneficial duringbraking and turning of the vehicle 100 to counteract brake dive, duringbraking, and body roll during turns. In accordance with one embodimentof the present disclosure, the electronic controller 120 processes inputsignals from one or more sensors (not shown) of the vehicle 100 in orderto control the damping level of each of the dampers 112. The sensors maysense one or more parameters of the vehicle 100, such as, but notlimited to, displacement, velocity, acceleration, vehicle speed,steering wheel angle, brake pressure, engine torque, engine revolutionsper minute (RPM), throttle pedal position, and so forth. The electroniccontroller 120 may further control the damping level of the dampers 112based on a driving mode of the vehicle 100. The driving mode may includea sport mode and a comfort mode. A button (not shown) may allow a driverof the vehicle 100 to choose the driving mode of the vehicle 100. Theelectronic controller 120 may receive input signals based on anactuation of the button and control the dampers 112 accordingly.

In accordance with another embodiment of the present disclosure, theelectronic controller 120 controls the damping level of each of thedampers 112 based on external road conditions, such as rain, snow, mud,and the like. In a further embodiment, the electronic controller 120regulates the damping level of each of the dampers 112 based on internalvehicle conditions, such as a fuel level, occupancy of the vehicle,load, and so forth.

While the present disclosure is being illustrated with a singleelectronic controller 120, it is within the scope of the presentdisclosure to utilize a dedicated electronic controller for each of thedampers 112. The dedicated electronic controller may be located onboardeach respective damper 112. Alternatively, the electronic controller 120may be integrated into an Electronic Control Unit (ECU) of the vehicle100. The electronic controller 120 may include a processor, memory,Input/Output (I/O) interfaces, communication interfaces, and otherelectrical components. The processor may execute various instructionsstored in the memory for carrying out various operations of theelectronic controller 120. The electronic controller 120 may receive andtransmit signals and data through the I/O interfaces and thecommunication interfaces. In further embodiments, the electroniccontroller 120 may include microcontrollers, application-specificintegrated circuits (ASICs), field programmable gate arrays (FPGAs), andso forth.

FIGS. 2 and 3 illustrate an exemplary damper 112. The damper 112 may beany of the four dampers 112 of the vehicle 100. The damper 112 mayoptionally be configured as a Continuously Variable Semi-ActiveSuspension system damper 112. The damper 112 contains a fluid. By way ofexample and without limitation, the fluid is hydraulic fluid or oil. Thedamper 112 includes an inner tube 122 that extends longitudinallybetween a first inner tube end 156 and a second inner tube end 157. Apiston 124 is slidably disposed within the inner tube 122. The piston124 defines a first working chamber 126 and a second working chamber 128within the inner tube 122. Each of the first and second working chambers126, 128 contain the fluid therein. The first working chamber 126 ispositioned longitudinally between the piston 124 and the first innertube end 156 and acts as a rebound chamber during movement of the piston124. The second working chamber 128 is positioned longitudinally betweenthe piston 124 and the second inner tube end 157 and acts as acompression chamber. The volume of the first and second working chambers126, 128 varies based on the movement of the piston 124. The piston 124seals against the inside of the inner tube 122.

In the illustrated example, the piston 124 is free of orifices orpassages such that there is no fluid flow through the piston 124. Inother words, fluid in the first working chamber 126 cannot pass throughthe piston 124 into the second working chamber 128 or vice versa.However, alternative configurations are possible where the piston 124includes valving (not shown) to limit high internal pressures within thefirst and second working chambers 126, 128.

The damper 112 includes a piston rod 134. The piston rod 134 iscoaxially aligned with and defines a longitudinal axis A. One end of thepiston rod 134 is connected to the piston 124 and reciprocates with thepiston 124 whereas an opposite end of the piston rod 134 includes anattachment fitting 135 a that is configured to be connected to acomponent of the suspension system 102 or the body 104 of the vehicle100.

The damper 112 also includes an outer tube 136 disposed annularly aroundthe inner tube 122 and includes an inner cylindrical surface 129 thatfaces and is spaced from the inner tube 122. In some embodiments, theouter tube 136 is concentrically disposed around the inner tube 122. Theouter tube 136 extends longitudinally between a first outer tube end 137and a second outer tube end 139. The piston rod 134 extendslongitudinally out through the first outer tube end 137. The outer tube136 includes a closed portion 145 at the second outer tube end 139 and acylindrical portion 147 that extends from the first outer tube end 137to the closed portion 145 at the second outer tube end 139. Optionally,an attachment fitting 135 b is mounted to the closed portion 145 of theouter tube 136. The attachment fitting 135 b is provided in the form ofa hole, loop, threaded stud, or other attachment structure and isconfigured to attach to a component of the suspension system 102 or thebody 104 of the vehicle 100.

The damper 112 further includes a fluid transport chamber 138 that isdisposed between the inner tube 122 and the outer tube 136. The pistonrod 134 extends longitudinally through a rod guide 141, which is housedinside the first outer tube end 137. In the illustrated embodiment, theentire rod guide 141 is received within the first outer tube end 137while only a portion of the rod guide 141 is received within the firstinner tube end 156. The rod guide 141 includes a rod guide passage 143that is arranged in fluid communication with and that extends betweenthe first working chamber 126 and the fluid transport chamber 138.Stated another way, the fluid transport chamber 138 is arranged in fluidcommunication with the first working chamber 126 via the rod guidepassage 143.

Further, the damper 112 includes a cover member 148 attached to theouter tube 136. A collector chamber 152 is defined between the covermember 148 and the outer tube 136. The collector chamber 152 ispositioned external to (i.e., radially outward of) the outer tube 136.

In the illustrated example, the collector chamber 152 has a limitedcircumferential extent that extends about the outer tube in an arc 149that is less than or equal to 180 degrees. In other words, the collectorchamber 152 in the illustrated example is a pocket that runs along oneside of the outer tube 136 and is therefore distinguishable from anannular chamber, such as an annular chamber created by another tubedisposed about the outer tube 136. The outer tube 136 has an outer tubelength OL that is measured longitudinally between the first and secondouter tube ends 137, 139 and the collector chamber 152 has a collectorchamber length CL that is measured longitudinally between first andsecond collector ends 151, 153. The collector chamber length CL isshorter than the outer tube length OL. In other words, the collectorchamber 152 is shorter than the outer tube 136 and does not run alongthe entire length of the outer tube 136. Four ports 140, 142, 144, 146extend through the outer tube 136 at longitudinally spaced locationsthat are aligned with the collector chamber 152 (i.e., that arepositioned within the collector chamber length CL).

The damper 112 also includes an intake valve assembly 154 with anadapter ring 130 that is press-fit into the second inner tube end 157.The adapter ring 130 can be made in different variations with differentouter diameters such that a standardized intake valve assembly 154 canbe fitted in dampers with inner tubes 122 of different diameters. Theintake valve assembly 154 is disposed inside the outer tube 136 andincludes a first intake valve body 155 a that abuts the adapter ring130, a second valve body 155 b that is longitudinally spaced from thefirst intake valve body 155 a, and a divider body 155 c that ispositioned longitudinally between the first and second intake valvebodies 155 a, 155 b. The intake valve assembly 154 also includes aspacer 150 that is positioned longitudinally between the second intakevalve body 155 b and the divider body 155 c.

The first and second intake valve bodies 155 a, 155 b and the dividerbody 155 c abut the inner cylindrical surface 129 of the outer tube 136to define first and second intermediate chambers 159 a, 159 b inside theouter tube 136. The first intermediate chamber 159 a is positionedlongitudinally between the first intake valve body 155 a and the dividerbody 155 c. The second intermediate chamber 159 b is positionedlongitudinally between the second intake valve body 155 b and thedivider body 155 c. An accumulation chamber 162 is positionedlongitudinally between the second intake valve body 155 b and the secondouter tube end 139. The first intake valve body 155 a forms a partitionbetween the first intermediate chamber 159 a and the fluid transportchamber 138, the second intake valve body 155 b forms a partitionbetween the second intermediate chamber 159 b and the accumulationchamber 162, and the divider body 155 c forms a partition between thefirst and second intermediate chambers 159 a, 159 b.

Although other configurations may be possible, in the illustratedexample, each of the first and second intake valve bodies 155 a, 155 band the divider body 155 c has a cylindrical hub portion and a disc-likeflange such that the first and second intake valve bodies 155 a, 155 band the divider body 155 c have shapes similar to that of a top hat. Thefirst and second intake valve bodies 155 a, 155 b and the divider body155 c can be pre-assembled prior to insertion into the damper 112 by afastener 169 such as a bolt or a rivet that clamps the first and secondintake valve bodies 155 a, 155 b and the divider body 155 c together.

The first intermediate chamber 159 a and the accumulation chamber 162are each arranged in fluid communication with the collector chamber 152via ports 144, 146 in the outer tube 136. With additional reference toFIGS. 6 and 7, the first intake valve body 155 a includes a first set ofpassages 158 a and a first set of intake orifices 158 b that extendthrough the first intake valve body 155 a. The first set of intakeorifices 158 b are arranged circumferentially around (i.e., are radiallyoutward of) the first set of passages 158 a. The divider body 155 cincludes a second set of passages 158 c. The first set of passages 158 ain the first intake valve body 155 a are aligned with and arranged influid communication with the second set of passages 158 c in the secondintake valve body 155 b. As a result, fluid can flow between the secondintermediate chamber 159 b and the second working chamber 128 via thefirst and second set of passages 158 a, 158 c. The second intake valvebody 155 b includes a second set of intake orifices 158 d that extendthrough the second intake valve body 155 b.

The first set of intake orifices 158 b allow fluid communication betweenthe first intermediate chamber 159 a and the fluid transport chamber138. The intake valve assembly 154 further comprises a first intakevalve 165 a that controls fluid flow through the first set of intakeorifices 158 b between the first intermediate chamber 159 a and thefluid transport chamber 138. In the illustrated example, the firstintake valve 165 a is a passive valve. More specifically, in theillustrated embodiment, the first intake valve 165 a includes a firstspring disc stack 167 a that is mounted to the first intake valve body155 a. In operation, the first spring disc stack 167 a opens and closesthe first intake orifices 158 b by flexing towards and away from thefirst intake valve body 155 a based on a pressure differential betweenthe first intermediate chamber 159 a and the fluid transport chamber138. The first intake valve 165 a acts as a one-way valve that permitsfluid flow in only one direction from the first intermediate chamber 159a to the fluid transport chamber 138. As will be explained in greaterdetail below, this one-way flow through the first intake valve 165 aoccurs during compression strokes, which is where the piston 124 movestoward the intake valve assembly 154.

The second set of intake orifices 158 d allow fluid communicationbetween the accumulation chamber 162 and the second intermediate chamber159 b. The intake valve assembly 154 further comprises a second intakevalve 165 b that controls fluid flow through the second set of intakeorifices 158 d between the accumulation chamber 162 and the secondintermediate chamber 159 b. In the illustrated example, the secondintake valve 165 b is a passive valve. More specifically, in theillustrated embodiment, the second intake valve 165 b includes a secondspring disc stack 167 b that is mounted to the second intake valve body155 b. In operation, the second spring disc stack 167 b opens and closesthe second set of intake orifices 158 d by flexing towards and away fromthe second intake valve body 155 b based on a pressure differentialbetween the accumulation chamber 162 and the second intermediate chamber159 b. The second intake valve 165 b acts as a one-way valve thatpermits fluid flow in only one direction from the accumulation chamber162 and the second intermediate chamber 159 b. As will be explained ingreater detail below, this one-way flow through the second intake valve165 b occurs during extension strokes, which is where the piston 124moves away from the intake valve assembly 154. Optionally, the intakevalve assembly 154 may have one or more permanent bleed passages. Forexample, the intake valve assembly 154 may include extra slotted discs(not shown) between the first and second spring disc stacks 167 a, 167 band the first and second intake valve bodies 155 a, 155 b.Alternatively, small indents (not shown) can be provided in the sealingland of the first and second intake valve bodies 155 a, 155 b.

In accordance with the illustrated embodiment, the damper 112 includesan accumulator insert 160 that is disposed within the second outer tubeend 139. The accumulator insert 160 includes an accumulator sleeve 166,a floating piston 161, and a pressurized chamber (e.g., a gas chamber)163. The accumulator sleeve 166 is positioned inside the outer tube 136and extends between a closed end 173 adjacent to the second outer tubeend 139 and an open end 174 adjacent to the intake valve assembly 154.The floating piston 161 is preassembled inside the accumulator sleeve166 in a sliding fit. The pressurized chamber 163 is sealably separatedfrom the accumulation chamber 162 by the floating piston 161. Therefore,the accumulation chamber 162 is positioned longitudinally between theintake valve assembly 154 and the floating piston 161 and at least partof the accumulation chamber 162 is disposed inside the accumulatorsleeve 166. The accumulator chamber 162 contains a fluid and is arrangedin fluid communication with the collector chamber 152 via a third port(i.e., an accumulator port) 144 in the outer tube and an aperture 175 inthe accumulator sleeve 166 that is arranged in fluid communication withthe third port/accumulator port 144 (i.e., the aperture 175 in theaccumulator sleeve 166 is aligned with the third port/accumulator port144 in the outer tube 136). It should be appreciated that the termaperture, as used herein, is meant to include holes, orifices,passageways, slots, cut-outs, or other structures capable ofcommunicating fluid between the accumulation chamber 162 and thecollector chamber 152. The pressurized chamber 163 is positionedlongitudinally between the floating piston 161 and the closed end 173.The pressurized chamber 163 contains a pressurized fluid, such as a gas,that operates to bias the floating piston 161 towards the intake valveassembly 154.

The accumulator sleeve 166 extends longitudinally between the secondouter tube end 139 and the intake valve assembly 154 such that theclosed end 173 of the accumulator sleeve 166 abuts (i.e., contacts) theclosed portion 145 of the second outer tube end 139 and such that theopen end 174 of the accumulator sleeve 166 abuts the second intake valvebody 155 b of the intake valve assembly 154. Optionally, the closed end173 of the accumulator sleeve 166 may be configured to have a shallowercurvature than the closed portion 145 of the second outer tube end 139to create a ring-shaped contact area between the closed end 173 of theaccumulator sleeve 166 and the closed portion 145 of the second outertube end 139. This ring-shaped contact area functions to help center theaccumulator insert 160 within the second outer tube end 139, providesgreater load bearing surface area to support a preload force over apoint contact, and helps prevent rotation between the accumulator sleeve166 and the outer tube 136 by increasing friction over a point contact.

The accumulator sleeve 166 is arranged in a slip fit within the outertube 136 and applies a preload on the intake valve assembly 154 suchthat the intake valve assembly 154 is clamped between the open end 174of the accumulator sleeve 166 and the second inner tube end 157 of innertube 122. This pre-load also prevents the accumulator sleeve 166 fromrotating relative to the outer tube 136 such that the alignment of theaperture 175 in the accumulator sleeve 166 and the thirdport/accumulator port 144 in the outer tube 136 is maintained afterassembly. In accordance with this arrangement, the first and secondintake valve bodies 155 a, 155 b and the divider body 155 c do not needto be mechanically attached to the outer tube 136 (such as by welding)because the intake valve assembly 154 is held in place by theaccumulator sleeve 166 and the inner tube 122. Instead, O-ring seals176, positioned on the first and second intake valve bodies 155 a, 155 band the divider body 155 c, are arranged in sealing contact with theinside cylindrical surface 129 of the outer tube 136.

In accordance with this embodiment, manufacturing and assembly of thedamper 112 is less complicated, more efficient, and more economical.Both the intake valve assembly 154 and the accumulator insert 160 can bepre-assembled prior to installation inside the outer tube 136. By way ofexample and without limitation, the pressurized chamber 163 can becharged with a pressurized gas at a pressure of 3 to 8 Bar while thefloating piston 161 is inserted into the open end 174 of the accumulatorsleeve 166. An indent 179 can then be applied to the accumulator sleeve166 to prevent the pressurized gas in the pressurized chamber 163 frompushing the floating piston 161 out through the open end 174 in theaccumulator sleeve 166. The entire pre-assembled accumulator insert 160can then be inserted into the outer tube 136. Next, the entirepre-assembled intake valve assembly 154 can be inserted into the outertube 136. Finally, the inner tube 122 can be inserted into the outertube 136 until the second inner tube end 157 contacts the adapter ring130 of the intake valve assembly 154, the piston 124 and piston rod 134can be inserted in the inner tube 122, and then the rod guide 141 can bepressed into the first inner tube end 156 and the first outer tube end137 at a preload. By way of example and without limitation, a preloadforce of approximately 10 kilonewtons (kN) can be used. All of thesesteps can be done without any welding operations.

For example, an exemplary method of manufacturing the damper 112 is setforth below. The method beings with the steps of: forming the outer tube136 with a first outer tube end 137 that is open and a second outer tubeend 139 that has a closed portion 145, forming the inner tube 122 with afirst inner tube end 156 and a second inner tube end 157, and creatingthe pre-assembled intake valve assembly 154. The step of creating thepre-assembled intake valve assembly 154 includes fastening the first andsecond intake valve bodies 155 a, 155 b to the divider body 155 c, whichmay be done using a bolt, rivet, or other fastener. The method furtherincludes the steps of: forming the accumulator sleeve 166 with a closedend 173 and an open end 174, filling the accumulator sleeve 166 with apressurized gas, and inserting a floating piston 161 into the open end174 of the accumulator sleeve 166 to create the pre-assembledaccumulator insert 160. The method may also include the steps of:forming the accumulator port 144 in the outer tube 136 and the collectorchamber 152 (which is arranged in fluid communication with theaccumulator port 144), forming the aperture 175 in the accumulatorsleeve 166 (which is arranged in fluid communication with theaccumulator port 144 by aligning the aperture 175 with the accumulatorport 144), and forming an indent 179 in the accumulator sleeve 166 afterthe step of inserting the floating piston 161 into the open end 174 ofthe accumulator sleeve 166 to prevent the pressurized gas in thepressurized chamber 163 from pushing the floating piston 161 back outthrough the open end 174 of the accumulator sleeve 166.

The method then proceeds with the steps of: inserting the pre-assembledaccumulator insert 160 into the first outer tube end 137, inserting thepre-assembled intake valve assembly 154 into the first outer tube end137, and inserting the inner tube 122 into the first outer tube end 137.The piston 124 and piston rod 134 are inserted in the inner tube 122 andthe rod guide 141 is pressed into the first inner tube end 156 and thefirst outer tube end 137 at a pre-determined preload, which presses thesecond inner tube end 157 into contact with the adapter ring 130 of theintake valve assembly 154, the pre-assembled intake valve assembly 154into contact with the open end 174 of the accumulator sleeve 166, andthe closed end 173 of the accumulator sleeve 166 into contact with theclosed portion 145 of the second outer tube end 139. In accordance withthis method, all welding, heat treating, and painting operations on theouter tube 136 are completed before the steps of inserting thepre-assembled intake valve assembly 154 and the pre-assembledaccumulator insert 160 into the outer tube 136.

There are a number of advantages associated with the present design.First, filling pressurized chamber 163 with a pressurized gas while theaccumulator insert 160 is outside of the damper 112 is easier thanfilling the second outer tube end 139 with a pressurized gas, whichtypically required a separate filling port or welded end cap on thesecond outer tube end 139. Second, by moving the floating piston 161 toan accumulator insert sub-assembly 160, the present design also makes iteasier to coat the outer tube 136 with paint/coatings that require hightemperature curing because typical seals used on the floating piston 161cannot withstand high temperatures. Third, attachments such as theattachment fitting 135 b and the cover member 148 can be welded to theouter tube 136 without affecting the sealing surface for the floatingpiston 161 because the floating piston 161 slides against the insidesurface of the accumulator sleeve 166 instead of the inner cylindricalsurface 129 of the outer tube 136. The heat generated by weldingoperations can cause distortion and create variances (i.e., change) inpart geometries, which can negatively affect the operation and sealingof the floating piston 161. The disclosed design resolves this problembecause no welding operations are required on the accumulator sleevealong the travel path of the floating piston 161 and all weldingoperations on the outer tube 136 are completed before the accumulatorinsert 160 is inserted into the outer tube 136.

The damper 112 includes first and second control valves 164 a, 164 bthat are externally mounted to the outer tube 136. In the illustratedexample, the first and second control valves 164 a, 164 b aretwo-position, solenoid actuated electro-hydraulic valves. However, itshould be appreciated that other types of active (e.g., electric) orpassive (e.g., mechanical) externally mounted valves can be used. Aswill be explained in greater detail below, the first control valve 164 ais operable to regulate fluid flow from the fluid transport chamber 138to the collector chamber 152 and the second control valve 164 b isoperable to regulate fluid flow from the second intermediate chamber 159b to the collector chamber 152. The first control valve 264 a includes afirst valve member 171 a that is moveable along a first control valveaxis VA1 between an open position and a closed position. The secondcontrol valve 264 b includes a second valve member 171 b that ismoveable along a second control valve axis VA2 between an open positionand a closed position. Although other configurations are possible, inthe illustrated embodiment, wherein the first and second control valveaxes VA1 and VA2 are parallel and longitudinally spaced apart from oneanother and are arranged perpendicular to the longitudinal axis A of thepiston rod 134.

The electronic controller 120 may regulate the first and second controlvalves 164 a, 164 b in order to control the damping level of the damper112. The first and second control valves 164 a, 164 b may be controlledby input currents provided to the solenoids of the first and secondcontrol valves 164 a, 164 b. The electronic controller 120 generates theinput current in order to control the operation and the damping level ofthe damper 112. The solenoids of the first and second control valves 164a, 164 b may be connected in electrical communication with theelectronic controller 120. Further, the input current may vary betweenlower and upper limits, which correspond to the least and mostrestrictive positions (i.e., an open position and a closed position) ofthe first and second control valves 164 a, 164 b. The electroniccontroller 120 may control the damping force or level by controlling adegree of restriction of the first and second control valves 164 a, 164b. Specifically, the electronic controller 120 may regulate the inputcurrents to vary the restriction of the first and second control valves164 a, 164 b. Sending a low current to the first and second controlvalves 164 a, 164 b may correspond to a low damping ratio or dampinglevel. Similarly, sending a high current to the first and second controlvalves 164 a, 164 b may correspond to a high damping ratio or dampinglevel.

The first control valve 164 a has a first control valve inlet 170 a thatis arranged in fluid communication with the fluid transport chamber 138between the inner and outer tubes 122, 136 and a first control valveoutlet 172 a that is arranged in fluid communication with the collectorchamber 152. The first port 140 in the outer tube 136 is arranged influid communication with and extends between the fluid transport chamber138 and the first control valve inlet 170 a.

The second control valve 164 b has a second control valve inlet 170 bthat is arranged in fluid communication with the second intermediatechamber 159 b and a second control valve outlet 172 b that is arrangedin fluid communication with the collector chamber 152. The second port142 in the outer tube 136 is arranged in fluid communication with andextends between the second intermediate chamber 159 b and the secondcontrol valve inlet 170 b. The third port 144 in the outer tube 136 isarranged in fluid communication with and extends between the collectorchamber 152 and the accumulation chamber 162. The fourth port 146 in theouter tube 136 is arranged in fluid communication with and extendsbetween the collector chamber 152 and the first intermediate chamber 159a. As a result, the accumulator chamber 162 is arranged in fluidcommunication with the collector chamber 152 via the third port 144 inthe outer tube 136 and the first intermediate chamber 159 a is arrangedin fluid communication with the collector chamber 152 via the fourthport 146 in the outer tube 136.

During an extension (i.e., rebound) stroke of the damper 112, the firstcontrol valve 164 a is operable to regulate fluid flow from the fluidtransport chamber 138 to the collector chamber 152 in response tomovement of the piston 124 towards the rod guide 141. The first controlvalve 164 a is in the open position during extension strokes of thedamper 112 to control rebound damping characteristics of the damper 112.Specifically, the degree of opening of the first control valve 164 a maybe regulated to adjust the extension/rebound damping characteristics ofthe damper 112. The second control valve 164 b is in the closed positionduring extension strokes of the damper 112. As a result, there is nocommunication of fluid directly between the second intermediate chamber159 b and the collector chamber 152 during an extension stroke.

During a compression stroke, the second control valve 164 b is operableto regulate fluid flow from the second intermediate chamber 159 b to thecollector chamber 152 in response to movement of the piston 124 towardsthe intake valve assembly 154. The second control valve 164 b is in theopen position during compression strokes of the damper 112 to controlcompression damping characteristics of the damper 112. Specifically, thedegree of opening of the second control valve 164 b may be regulated toadjust the compression damping characteristics of the damper 112. Thefirst control valve 164 a is in the closed position during compressionstrokes of the damper 112. As a result, there is no communication offluid directly between the fluid transport chamber 138 and the collectorchamber 152 during a compression stroke.

In the illustrated example, each of the first and second control valves164 a, 164 b includes a control valve housing 168 a, 168 b. A portion ofeach control valve housing 168 a, 168 b is received within and extendsthrough the cover member 148. Though the first and second ports 140, 142in the outer tube 136 are illustrated as circular apertures in FIG. 2,the shape and dimensions of the first and second ports 140, 142 in theouter tube 136 may be based on any shape and dimensions of the controlvalve housings 168 a, 168 b.

In the open position, the first control valve 164 a allows fluidcommunication between the fluid transport chamber 138 and the collectorchamber 152. More particularly, the first control valve inlet 170 a isin fluid communication with the fluid transport chamber 138 and thefirst control valve outlet 172 a is in fluid communication with thecollector chamber 152. The first valve member 171 a allows selectivefluid communication between the first control valve inlet 170 a and thefirst control valve outlet 172 a and therefore selective fluid flowbetween the fluid transport chamber 138 and the collector chamber 152,which ultimately regulates fluid flow from the first working chamber 126to the accumulation chamber 162.

In the open position, the second control valve 164 b allows fluidcommunication between the first intermediate chamber 159 a and thecollector chamber 152. More particularly, the second control valve inlet170 b is in fluid communication with the first intermediate chamber 159a and the second control valve outlet 172 b is in fluid communicationwith the collector chamber 152. The second valve member 171 b allowsselective fluid communication between the second control valve inlet 170b and the second control valve outlet 172 b and therefore selectivefluid flow between the first intermediate chamber 159 a and thecollector chamber 152, which ultimately regulates fluid flow from thesecond working chamber 128 to the accumulation chamber 162.

The intake valve assembly 154 allows bi-directional flow of fluidbetween the accumulation chamber 162 to the second working chamber 128.During compression strokes, the volume of the first working chamber 126increases as the piston 124 moves towards the intake valve assembly 154.The first intake valve 165 a in the intake valve assembly 154 provides acompensating fluid flow where fluid from the second control valve outlet172 b flows into the collector chamber 152, through the fourth port 146in the outer tube 136, through the first intermediate chamber 159 a,through the first set of intake orifices 158 b in the first intake valvebody 155 a, into the fluid transport chamber 138, and ultimately intothe first working chamber 126 to increase the amount of fluid in thefirst working chamber 126. During extension/rebound strokes, the volumeof the first working chamber 126 decreases as the piston 124 moves awayfrom the intake valve assembly 154. The second intake valve 165 b in theintake valve assembly 154 provides a compensating fluid flow where fluidin the accumulation chamber 162 flows through the intake valve assembly154 and into the second working chamber 128 to increase the amount offluid in the second working chamber 128.

Operation of the damper 112 during the rebound and compression strokeswill now be explained in greater detail.

With reference to FIG. 4, the damper 112 is shown in a compressionstroke, which occurs when the piston 124 moves towards the intake valveassembly 154. During a compression stroke, the volume of the fluid inthe first working chamber 126 that is displaced by the piston rod 134increases and the volume of the second working chamber 128 decreases. Anadditional flow of fluid must be supplied to the first working chamber126 to compensate for the increase in the volume of the first workingchamber 126. Further, during the compression stroke, there is a net flowof fluid into the accumulation chamber 162, which causes the floatingpiston 161 to move away from the intake valve assembly 154, increasingthe size of the accumulation chamber 162. This net flow of fluid intothe accumulation chamber 162 occurs due to the increase in the volume ofthe piston rod 134 in the first working chamber 126.

During a compression stroke, the first control valve 164 a is in aclosed position, the second control valve 164 b is in an open position,and the piston 124 moves towards the intake valve assembly 154. Acompression flow path P1 is defined inside the damper 112, where fluidin the second working chamber 128 flows through the first set ofpassages 158 a in the first intake valve body 155 a, through the secondset of passages 158 c in the divider body 155 c, and into the secondintermediate chamber 159 b. Fluid in the second intermediate chamber 159b flows to the second control valve inlet 170 b and passes through thesecond port 142 in the outer tube 136. Fluid from the second controlvalve inlet 170 b flows to the second control valve outlet 172 b becausethe second control valve 164 b is in the open position and fluid fromthe second control valve outlet 172 b flows into the collector chamber152. The fluid flowing into the collector chamber 152 flows into theaccumulation chamber 162 via the third port 144 in the outer tube 136and into the first intermediate chamber 159 a via the fourth port 146.If the pressure differential between the first intermediate chamber 159a and the fluid transport chamber 138 exceeds the break pressure of thefirst intake valve 165 a, the first intake valve 165 a will open andfluid will flow through the first set of intake orifices 158 b in thefirst intake valve body 155 a, through the fluid transport chamber 138,and through the rod guide passages 143 into the first working chamber126, which increases in volume during compression strokes.

With reference to FIG. 5, the damper 112 is shown in anextension/rebound stroke, which occurs when the piston 124 moves awayfrom the intake valve assembly 154. During the extension/rebound stroke,the volume of the fluid in the first working chamber 126 that isdisplaced by the piston rod 134 decreases and the volume of fluid in thesecond working chamber 128 increases. An additional flow of fluid mustbe supplied to the second working chamber 128 to compensate for theincrease in the volume of the second working chamber 128. In order toincrease the amount of fluid in the second working chamber 128, someportion of the fluid from the accumulation chamber 162 flows through theintake valve assembly 154 and into the second working chamber 128 suchthat an extension flow path P2 is defined within the damper 112.Further, during the extension/rebound stroke, there is a net flow offluid out of the accumulation chamber 162, which causes the floatingpiston 161 to move towards the intake valve assembly 154, decreasing thesize of the accumulation chamber 162. This net flow of fluid out of theaccumulation chamber 162 occurs due to the decrease in the volume of thepiston rod 134 in the first working chamber 126.

During an extension/rebound stroke, the first control valve 164 a is inan open position, the second control valve 164 b is in a closedposition, and the piston 124 moves away from the intake valve assembly154. Fluid in the first working chamber 126 flows into the fluidtransport chamber 138 via the rod guide passages 143. Fluid in the fluidtransport chamber 138 then flows to the first control valve inlet 170 aand passes through the first port 140 in the outer tube 136. Fluid fromthe first control valve inlet 170 a flows to the first control valveoutlet 172 a because the first control valve 164 a is in the openposition and fluid from the first control valve outlet 172 a flows intothe collector chamber 152. Fluid from the collector chamber 152 flowsinto the accumulation chamber 162 via the third port 144 in the outertube 136. Finally, fluid in the accumulation chamber 162 flows throughthe intake valve assembly 154 and into the second working chamber 128.When the pressure differential between the accumulation chamber 162 andthe second intermediate chamber 159 b exceeds the break pressure of thesecond intake valve 165 b, the second intake valve 165 b will open andfluid in the accumulation chamber 162 will flow through the second setof intake orifices 158 d in the second intake valve body 155 b, throughthe second intermediate chamber 159 b, through the second set ofpassages 158 c in the divider body 155 c, through the first set ofpassages 158 a in the first intake valve body 155 a, and into the secondworking chamber 128, which increases in volume during extension/reboundstrokes.

FIGS. 8 and 9 illustrate another exemplary damper 112′, with an intakevalve assembly 154′ of an alternative configuration. Many of theelements of the damper 112′ shown in FIGS. 8 and 9 are the same as theelements of the damper 112 shown in FIGS. 2 and 3 and therefore sharethe same reference numbers. The elements in FIGS. 8 and 9 that are new,different, or have been modified are labeled with reference numberswhere a prime (′) annotation has been appended after the referencenumeral.

The intake valve assembly 154′ is disposed inside the outer tube 136 andincludes a first intake valve body 155 a′ that abuts the adapter ring130, a second valve body 155 b′, and a divider body 155 c′. Inaccordance with this alternative arrangement, the second valve body 155b′ is positioned longitudinally between the first intake valve body 155a′ and the divider body 155 c′. The intake valve assembly 154′ alsoincludes a spacer 150′ that is positioned longitudinally between thesecond intake valve body 155 b′ and the divider body 155 c′.

The first and second intake valve bodies 155 a′, 155 b′ and the dividerbody 155 c′ abut the inner cylindrical surface 129 of the outer tube 136to define first and second intermediate chambers 159 a′, 159 b′ insidethe outer tube 136. The first intermediate chamber 159 a′ is positionedlongitudinally between the first and second intake valve bodies 155 a′,155 b′. The second intermediate chamber 159 b′ is positionedlongitudinally between the second intake valve body 155 b′ and thedivider body 155 c′. An accumulation chamber 162′ is positionedlongitudinally between the divider body 155 c′ and the second outer tubeend 139. The first intake valve body 155 a′ forms a partition betweenthe first intermediate chamber 159 a′ and the fluid transport chamber138, the second intake valve body 155 b′ forms a partition between thefirst and second intermediate chambers 159 a′, 159 b′, and the dividerbody 155 c′ forms a partition between the second intermediate chamber159 b′ and the accumulation chamber 162′.

In accordance with this embodiment, the damper 112′ includes anaccumulator insert 160′ that is disposed within the second outer tubeend 139. The accumulator insert 160′ includes an accumulator sleeve166′, a floating piston 161, and a pressurized chamber (e.g., a gaschamber) 163. The accumulator sleeve 166′ is positioned inside the outertube 136 and extends between a closed end 173 adjacent to the secondouter tube end 139 and an open end 174′ adjacent to the intake valveassembly 154′. The floating piston 161 is preassembled inside theaccumulator sleeve 166′ in a sliding fit. The pressurized chamber 163 issealably separated from the accumulation chamber 162′ by the floatingpiston 161. Therefore, the accumulation chamber 162′ is positionedlongitudinally between the intake valve assembly 154′ and the floatingpiston 161 and at least part of the accumulation chamber 162′ isdisposed inside the accumulator sleeve 166′. The accumulator chamber162′ contains a fluid and is arranged in fluid communication with thecollector chamber 152 via the third port (i.e., the accumulator port)144 in the outer tube 136 and multiple aperture 175′ in the accumulatorsleeve 166′ that are arranged in fluid communication with the thirdport/accumulator port 144. The pressurized chamber 163 is positionedlongitudinally between the floating piston 161 and the closed end 173.The pressurized chamber 163 contains a pressurized fluid, such as a gas,that operates to bias the floating piston 161 towards the intake valveassembly 154′.

The accumulator sleeve 166′ extends longitudinally between the secondouter tube end 139 and the intake valve assembly 154′ such that theclosed end 173 of the accumulator sleeve 166′ abuts (i.e., contacts) theclosed portion 145 of the second outer tube end 139 and such that theopen end 174′ of the accumulator sleeve 166 abuts the divider body 155c′ of the intake valve assembly 154′. Again, the accumulator sleeve 166′is arranged in a slip fit within the outer tube 136 and applies apreload on the intake valve assembly 154′ such that the intake valveassembly 154′ is clamped between the open end 174′ of the accumulatorsleeve 166′ and the second inner tube end 157 of inner tube 122. Inaccordance with this arrangement, the first and second intake valvebodies 155 a′, 155 b′ and the divider body 155 c′ do not need to bemechanically attached to the outer tube 136 (such as by welding) becausethe intake valve assembly 154′ is held in place by the accumulatorsleeve 166′ and the inner tube 122. O-ring seals 176′, positioned on thefirst and second intake valve bodies 155 a′, 155 b′ and the divider body155 c′, are arranged in sealing contact with the inside cylindricalsurface 129 of the outer tube 136.

In accordance with this embodiment, the open end 174′ of the accumulatorsleeve 166′ has an inwardly tapering rim 177′. This inwardly taperingrim 177′ has a frusto-conical shape such that an annular gap 178′ iscreated between the inwardly tapering rim 177′ and the insidecylindrical surface 129 of the outer tube 136. This annular gap 178′ islongitudinally aligned and arranged in fluid communication with theaccumulator port/third port 144 in the outer tube 136. The apertures175′ in the accumulator sleeve 166′ are positioned along the inwardlytapering rim 177′ at circumferentially spaced locations such that fluidin the accumulation chamber 162′ can flow into the annular gap 178′ andthrough the accumulator port/third port 144 in the outer tube 136 or inthe opposite direction from the collector chamber 152 to theaccumulation chamber 162′. This arrangement therefore eliminates theneed to ensure alignment between the aperture(s) 175, 175′ and theaccumulator port/third port 144 in the outer tube 136. In addition, theinwardly tapering rim 177′ functions to retain the floating piston 161inside the accumulator sleeve 166′ after the pressurized chamber 163 hasbeen filled (i.e., charged) with pressurized gas.

Damper 112′ may be manufactured using the same method described above,but with the additional step of forming the inwardly tapering rim 177′at the open end 174′ of the accumulator sleeve 166′ after the step ofinserting the floating piston 161 into the open end 174′ of theaccumulator sleeve 166′ instead of forming the indent 179 in theaccumulator sleeve 166. This step of forming the inwardly tapering rim177′ prevents the pressurized gas in the accumulator insert 160′ frompushing the floating piston 161 back out through the open end 174′ ofthe accumulator sleeve 166′. In addition, the step of forming anaperture 175′ in the accumulator sleeve 166′ may include formingmultiple apertures 175′ at circumferentially spaced positions in theinwardly tapering rim 177′.

Although other configurations may be possible, in the illustratedexample, each of the first and second intake valve bodies 155 a′, 155 b′has a cylindrical hub portion and a disc-like flange such that the firstand second intake valve bodies 155 a′, 155 b′ have shapes similar tothat of a top hat. In this configuration, the divider body 155 c′ isshaped like a solid disk. In this embodiment, there are no orifices orpassages in the divider body 155 c′. As a result, the divider body 155c′ acts as a fluid flow obstruction such that there is no fluid flowthrough the divider body 155 c′. The first and second intake valvebodies 155 a′, 155 b′ and the divider body 155 c′ can be pre-assembledprior to insertion into the damper 112′ by a fastener 169′ such as abolt or a rivet that clamps the first and second intake valve bodies 155a′, 155 b′ and the divider body 155 c′ together.

The first intermediate chamber 159 a′ and the accumulation chamber 162are each arranged in fluid communication with the collector chamber 152via third and fourth ports 144, 146 in the outer tube 136. Withadditional reference to FIGS. 11 and 12, the first intake valve body 155a′ includes a first set of passages 158 a′ and a first set of intakeorifices 158 b′ that extend through the first intake valve body 155 a′.The first set of intake orifices 158 b′ are arranged circumferentiallyaround (i.e., are radially outward of) the first set of passages 158 a′.The second intake valve body 155 b′ includes a second set of passages158 c′ and a second set of intake orifices 158 d′ that extend throughthe second intake valve body 155 b′. The second set of intake orifices158 d′ are arranged circumferentially around (i.e., are radially outwardof) the second set of passages 158 c′. The first set of passages 158 a′in the first intake valve body 155 a′ are aligned with and arranged influid communication with the second set of passages 158 c′ in the secondintake valve body 155 b′. As a result, fluid can flow between the secondintermediate chamber 159 b′ and the second working chamber 128′ via thefirst and second set of passages 158 a′, 158 c′.

The first set of intake orifices 158 b′ allow fluid communicationbetween the first intermediate chamber 159 a′ and the fluid transportchamber 138. The intake valve assembly 154′ further comprises a firstintake valve 165 a′ that controls fluid flow through the first set ofintake orifices 158 b′ between the first intermediate chamber 159 a′ andthe fluid transport chamber 138. In the illustrated example, the firstintake valve 165 a′ is a passive valve. More specifically, in theillustrated embodiment, the first intake valve 165 a′ includes a firstspring disc stack 167 a′ that is mounted to the first intake valve body155 a′. In operation, the first spring disc stack 167 a′ opens andcloses the first intake orifices 158 b′ by flexing towards and away fromthe first intake valve body 155 a′ based on a pressure differentialbetween the first intermediate chamber 159 a′ and the fluid transportchamber 138. The first intake valve 165 a′ acts as a one-way valve thatpermits fluid flow in only one direction from the first intermediatechamber 159 a′ to the fluid transport chamber 138. As will be explainedin greater detail below, this one-way flow through the first intakevalve 165 a′ occurs during compression strokes, which is where thepiston 124 moves toward the intake valve assembly 154′.

The second set of intake orifices 158 d′ allow fluid communicationbetween the first and second intermediate chambers 159 a′, 159 b′. Theintake valve assembly 154′ further comprises a second intake valve 165b′ that controls fluid flow through the second set of intake orifices158 d′ between the first and second intermediate chambers 159 a′, 159b′. In the illustrated example, the second intake valve 165 b′ is apassive valve. More specifically, in the illustrated embodiment, thesecond intake valve 165 b′ includes a second spring disc stack 167 b′that is mounted to the second intake valve body 155 b′. In operation,the second spring disc stack 167 b′ opens and closes the second intakeorifices 158 d′ by flexing towards and away from the second intake valvebody 155 b′ based on a pressure differential between the firstintermediate chamber 159 a′ and the second intermediate chamber 159 b′.The second intake valve 165 b′ acts as a one-way valve that permitsfluid flow in only one direction from the first intermediate chamber 159a′ and the second intermediate chamber 159 b′. As will be explained ingreater detail below, this one-way flow through the second intake valve165 b′ occurs during extension strokes, which is where the piston 124moves away from the intake valve assembly 154′.

The intake valve assembly 154′ allows bi-directional flow of fluidbetween the accumulation chamber 162 to the second working chamber 128.During compression strokes, the volume of the first working chamber 126increases as the piston 124 moves towards the intake valve assembly154′. The first intake valve 165 a′ in the intake valve assembly 154′provides a compensating fluid flow where fluid from the second controlvalve outlet 172 b flows into the collector chamber 152, through thefourth port 146 in the outer tube 136, through the first intermediatechamber 159 a′, through the first set of intake orifices 158 b′ in thefirst intake valve body 155 a′, into the fluid transport chamber 138,and ultimately into the first working chamber 126 to increase the amountof fluid in the first working chamber 126. During extension/reboundstrokes, the volume of the first working chamber 126 decreases as thepiston 124 moves away from the intake valve assembly 154′. The secondintake valve 165 b′ in the intake valve assembly 154′ provides acompensating fluid flow where fluid in the accumulation chamber 162flows through the intake valve assembly 154′ and into the second workingchamber 128 to increase the amount of fluid in the second workingchamber 128.

Operation of the damper 112′ during the rebound and compression strokeswill now be explained in greater detail.

With reference to FIG. 9, the damper 112′ is shown in a compressionstroke, which occurs when the piston 124 moves towards the intake valveassembly 154′. During a compression stroke, the volume of the fluid inthe first working chamber 126 that is displaced by the piston rod 134increases and the volume of the second working chamber 128 decreases. Anadditional flow of fluid must be supplied to the first working chamber126 to compensate for the increase in the volume of the first workingchamber 126. Further, during the compression stroke, there is a net flowof fluid into the accumulation chamber 162, which causes the floatingpiston 161 to move away from the intake valve assembly 154′, increasingthe size of the accumulation chamber 162. This net flow of fluid intothe accumulation chamber 162 occurs due to the increase in the volume ofthe piston rod 134 in the first working chamber 126.

During a compression stroke, the first control valve 164 a is in aclosed position, the second control valve 164 b is in an open position,and the piston 124 moves towards the intake valve assembly 154′. Acompression flow path P1′ is defined inside the damper 112′, where fluidin the second working chamber 128 flows through the first set ofpassages 158 a′ in the first intake valve body 155 a′, through thesecond set of passages 158 c′ in the second intake valve body 155 b′,and into the second intermediate chamber 159 b′. Fluid in the secondintermediate chamber 159 b′ flows to the second control valve inlet 170b and passes through the second port 142 in the outer tube 136. Fluidfrom the second control valve inlet 170 b flows to the second controlvalve outlet 172 b because the second control valve 164 b is in the openposition and fluid from the second control valve outlet 172 b flows intothe collector chamber 152. Fluid from the collector chamber 152 flowsinto the accumulation chamber 162 via the third port 144 in the outertube 136 and into the first intermediate chamber 159 a′ via the fourthport 146. If the pressure differential between the first intermediatechamber 159 a′ and the fluid transport chamber 138 exceeds the breakpressure of the first intake valve 165 a′, the first intake valve 165 a′will open and fluid will flow through the first set of intake orifices158 b′ in the first intake valve body 155 a′, through the fluidtransport chamber 138, and through the rod guide passages 143 into thefirst working chamber 126, which increases in volume during compressionstrokes.

With reference to FIG. 10, the damper 112′ is shown in anextension/rebound stroke, which occurs when the piston 124 moves awayfrom the intake valve assembly 154′. During the extension/reboundstroke, the volume of the fluid in the first working chamber 126 that isdisplaced by the piston rod 134 decreases and the volume of fluid in thesecond working chamber 128 increases. An additional flow of fluid mustbe supplied to the second working chamber 128 to compensate for theincrease in the volume of the second working chamber 128. In order toincrease the amount of fluid in the second working chamber 128, someportion of the fluid from the accumulation chamber 162 flows through theintake valve assembly 154′ and into the second working chamber 128 suchthat an extension flow path P2′ is defined within the damper 112′.Further, during the extension/rebound stroke, there is a net flow offluid out of the accumulation chamber 162, which causes the floatingpiston 161 to move towards the intake valve assembly 154′, decreasingthe size of the accumulation chamber 162. This net flow of fluid out ofthe accumulation chamber 162 occurs due to the decrease in the volume ofthe piston rod 134 in the first working chamber 126.

During an extension/rebound stroke, the first control valve 164 a is inan open position, the second control valve 164 b is in a closedposition, and the piston 124 moves away from the intake valve assembly154′. Fluid in the first working chamber 126 flows into the fluidtransport chamber 138 via the rod guide passages 143. Fluid in the fluidtransport chamber 138 then flows to the first control valve inlet 170 aand passes through the first port 140 in the outer tube 136. Fluid fromthe first control valve inlet 170 a flows to the first control valveoutlet 172 a because the first control valve 164 a is in the openposition and fluid from the first control valve outlet 172 a flows intothe collector chamber 152. Fluid from the collector chamber 152 flowsinto the accumulation chamber 162 via the third port 144 in the outertube 136 and into the first intermediate chamber 159 a′ via the fourthport 146. When the pressure differential between the first intermediatechamber 159 a′ and the second intermediate chamber 159 b′ exceeds thebreak pressure of the second intake valve 165 b′, the second intakevalve 165 b′ will open and fluid in the first intermediate chamber 159a′ will flow through the second set of intake orifices 158 d′ in thesecond intake valve body 155 b′, through the second intermediate chamber159 b′, through the second set of passages 158 c′ in the second intakevalve body 155 b′, through the first set of passages 158 a′ in the firstintake valve body 155 a′, and into the second working chamber 128, whichincreases in volume during extension/rebound strokes.

It should be appreciated that in this embodiment, the first and secondintake valve bodies 155 a′, 155 b′ are structurally identical and aresimply arranged in opposite orientations inside the outer tube 136 sothat the first intake valve 165 a′ is positioned on the side of thefirst intake valve body 155 a′ that is closer to the piston 124 and sothat the second intake valve 165 b′ is positioned on the side of thesecond intake valve body 155 b′ that is closer to the accumulationchamber 162. Because the first and second intake valve bodies 155 a′,155 b′ are structurally identical, this arrangement reduces themanufacturing cost of intake valve assembly 154′ compared to intakevalve assembly 154 where the first and second intake valve bodies 155 a,155 b need to be manufactured as two different components.

While aspects of the present disclosure have been particularly shown anddescribed with reference to the embodiments above, it will be understoodby those skilled in the art that various additional embodiments may becontemplated by the modification of the disclosed dampers withoutdeparting from the spirit and scope of what is disclosed. Suchembodiments should be understood to fall within the scope of the presentdisclosure as determined based upon the claims and any equivalentsthereof.

What is claimed is:
 1. A damper comprising: an inner tube extendinglongitudinally between a first inner tube end and a second inner tubeend; a piston slidably disposed within the inner tube defining a firstworking chamber and a second working chamber; an outer tube disposedaround the inner tube, the outer tube extending longitudinally between afirst outer tube end and a second outer tube end, the first workingchamber arranged in fluid communication with a fluid transport chamberdisposed between the inner tube and the outer tube; a collector chamberpositioned outside of the outer tube; an intake valve assemblypositioned within the outer tube and including a first intermediatechamber disposed in direct fluid communication with the collectorchamber at all times and a second intermediate chamber disposed indirect fluid communication with the second working chamber at all timesand a first intake valve that controls fluid flow through the intakevalve assembly between the first intermediate chamber and the fluidtransport chamber; and an accumulator insert comprising an accumulatorsleeve positioned inside the outer tube and extending between the secondouter tube end and the intake valve assembly, a floating piston slidablydisposed in the accumulator sleeve between the intake valve assembly andthe second outer tube end, and a pressurized chamber positionedlongitudinally between the floating piston and the second outer tubeend, the pressurized chamber containing a pressurized fluid thatoperates to bias the floating piston towards the intake valve assemblysuch that an accumulation chamber is defined between the intake valveassembly and the floating piston, wherein the accumulation chamber isarranged in fluid communication with the collector chamber.
 2. Thedamper of claim 1, wherein the accumulation chamber is arranged in fluidcommunication with the collector chamber via an accumulator port in theouter tube and at least one aperture in the accumulator sleeve that isarranged in fluid communication with the accumulator port.
 3. The damperof claim 2, wherein the intake valve assembly includes a first intakevalve body adjacent the second inner tube end, a second intake valvebody that is longitudinally spaced from the first intake valve body, anda divider body that is longitudinally spaced from the first and secondintake valve bodies, wherein the first intake valve is mounted to thefirst intake valve body and is configured to open and close a firstintake orifice in the first intake valve body, and wherein the first andsecond intake valve bodies and the divider body abut an insidecylindrical surface of the outer tube in a sliding fit.
 4. The damper ofclaim 3, wherein the intake valve assembly includes a second intakevalve that is mounted to the second intake valve body and is configuredto open and close a second intake orifice in the second intake valvebody.
 5. The damper of claim 4, wherein the divider body is positionedlongitudinally between the first and second intake valve bodies andwherein the first intermediate chamber is defined between the firstintake valve body and the divider body and wherein the secondintermediate chamber is connected in fluid communication with the secondworking chamber by a first passage that extends through the first intakevalve body and a second passage that extends through the divider bodyand that is arranged in fluid communication with the first passage. 6.The damper of claim 5, wherein the second intake valve body ispositioned between the accumulator chamber and the second intermediatechamber and the second intake valve is a one-way valve that permitsfluid flow through the second intake orifice in only one direction fromthe accumulator chamber to the second intermediate chamber.
 7. Thedamper of claim 4, wherein the second intake valve body islongitudinally positioned between the first intake valve body and thedivider body and wherein the first intermediate chamber is definedbetween the first and second intake valve bodies and wherein the secondintermediate chamber is connected in fluid communication with the secondworking chamber by a first passage that extends through the first intakevalve body and a second passage that extends through the second intakevalve body and that is arranged in fluid communication with the firstpassage.
 8. The damper of claim 7, wherein the divider body ispositioned between the accumulator chamber and the second intermediatechamber and is a fluid flow barrier that is free of orifices or passagessuch that there is no fluid flow through the divider body and whereinthe second intake valve is a one-way valve that permits fluid flowthrough the second intake orifice in only one-direction from the firstintermediate chamber to the second intermediate chamber.
 9. The damperof claim 3, wherein O-ring seals, positioned on the first and secondintake valve bodies and the divider body, are arranged in sealingcontact with the inside cylindrical surface of the outer tube.
 10. Thedamper of claim 1, wherein the accumulator sleeve includes a closed endthat abuts the second outer tube end and an open end that abuts theintake valve assembly such that the intake valve assembly is clampedbetween the open end of the accumulator sleeve and the second inner tubeend.
 11. The damper of claim 10, wherein the open end of the accumulatorsleeve has an inwardly tapering rim and wherein the at least oneaperture is positioned along the inwardly tapering rim of theaccumulator sleeve.
 12. The damper of claim 2, wherein the at least oneaperture in the accumulator sleeve is a single aperture that is alignedwith the accumulator port in the outer tube.
 13. The damper of claim 1,wherein the floating piston is preassembled inside the accumulatorsleeve and the accumulator sleeve is arranged in a slip fit with theouter tube and applies a preload on the intake valve assembly.
 14. Adamper comprising: an inner tube extending longitudinally between afirst inner tube end and a second inner tube end; a piston slidablydisposed within the inner tube defining a first working chamber and asecond working chamber; an outer tube disposed around the inner tube,the outer tube extending longitudinally between a first outer tube endand a second outer tube end, the first working chamber arranged in fluidcommunication with a fluid transport chamber disposed between the innertube and the outer tube; a collector chamber positioned outside of theouter tube; an intake valve assembly positioned within the outer tubeand including a first intermediate chamber disposed in direct fluidcommunication with the collector chamber at all times and a secondintermediate chamber disposed in direct fluid communication with thesecond working chamber at all times and at least one intake valve thatcontrols fluid flow through the intake valve assembly between the firstintermediate chamber and the fluid transport chamber; a first controlvalve externally mounted to the outer tube, the first control valvehaving a first control valve inlet that is arranged in fluidcommunication with the fluid transport chamber and a first control valveoutlet that is arranged in fluid communication with the collectorchamber; a second control valve externally mounted to the outer tube,the second control valve having a second control valve inlet that isarranged in fluid communication with the first intermediate chamber anda second control valve outlet that is arranged in fluid communicationwith the collector chamber; and an accumulator insert comprising anaccumulator sleeve positioned inside the outer tube and extendingbetween the second outer tube end and the intake valve assembly, afloating piston slidably disposed in the accumulator sleeve between theintake valve assembly and the second outer tube end, and a pressurizedchamber positioned longitudinally between the floating piston and thesecond outer tube end, the pressurized chamber containing a pressurizedfluid that operates to bias the floating piston towards the intake valveassembly such that an accumulation chamber is defined between the intakevalve assembly and the floating piston, wherein the accumulation chamberis arranged in fluid communication with the collector chamber via anaccumulator port in the outer tube and at least one aperture in theaccumulator sleeve that is arranged in fluid communication with theaccumulator port.